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Journal articles on the topic 'Imaging artefact'

Author: Grafiati

Published: 4 June 2021

Last updated: 1 February 2022

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1

GANAPATHI, M., G. JOSEPH, R. SAVAGE, A. R. JONES, B. TIMMS, and K. LYONS. "MRI Susceptibility Artefacts Related to Scaphoid Screws: the Effect of Screw Type, Screw Orientation and Imaging Parameters." Journal of Hand Surgery 27, no. 2 (April 2002): 165–70. http://dx.doi.org/10.1054/jhsb.2001.0717.

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Metal implants produce susceptibility artefacts in magnetic resonance imaging. We have explored the effects of scaphoid screw characteristics and orientation on MR susceptibility artefact. Titanium alloy, smallness and longitudinal alignment with the z-axis of the main magnetic field reduce the size of the susceptibility artefact.

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2

Tran, Lan Thi Xuan, Junichiro Sakamoto, Ami Kuribayashi, Hiroshi Watanabe, Hiroshi Tomisato, and Tohru Kurabayashi. "Quantitative evaluation of artefact reduction from metallic dental materials in short tau inversion recovery imaging: efficacy of syngo WARP at 3.0 tesla." Dentomaxillofacial Radiology 48, no. 7 (October 2019): 20190036. http://dx.doi.org/10.1259/dmfr.20190036.

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Objectives: To evaluate the effects of syngo WARP on reducing metal artefacts from dental materials. Methods: Short tau inversion recovery (STIR) with syngo WARP [a dedicated metal artefact reduction sequence in combination with view-angle-tilting (VAT)] was performed using phantoms of three dental alloys: cobalt–chromium (Co–Cr), nickel–chromium (Ni–Cr), and titanium (Ti). Artefact volumes and reduction ratios of black, white and overall artefacts in the standard STIR and syngo WARP images with several different parameter settings were quantified according to standards of the American Society for Testing and Materials F2119-07. In all sequences, the artefact volumes and reduction ratios were compared. The modulation transfer function (MTF) and contrast-to-noise ratio (CNR) were also measured for evaluation of image quality. Results: In standard STIR, the overall artefact volume of Co–Cr was markedly larger than those of Ni–Cr and Ti. All types of artefacts tended to be reduced with increasing receiver bandwidth (rBW) and VAT. The effect of artefact reduction tended to be more obvious in the axial plane than in the sagittal plane. Compared with standard STIR, syngo WARP with a matrix of 384 × 384, receiver bandwidth of 620 Hz/pixel, and VAT of 100 % in the axial plane obtained reduction effects of 30 % (white artefacts), 45 % (black artefacts), and 38 % (overall artefacts) although MTF and CNR decreased by 30 and 22 % compared with those of standard STIR, respectively. Conclusions: syngo WARP for STIR can effectively reduce metal artefacts from dental materials.

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Illanes, Alfredo, Johannes W. Krug, and Michael Friebe. "Assessing MRI susceptibility artefact through an indicator of image distortion." Current Directions in Biomedical Engineering 2, no. 1 (September 1, 2016): 427–31. http://dx.doi.org/10.1515/cdbme-2016-0095.

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AbstractSusceptibility artefacts in magnetic resonance imaging (MRI) caused by medical devices can result in a severe degradation of the MR image quality. The quantification of susceptibility artefacts is regulated by the ASTM standard which defines a manual method to assess the size of an artefact. This means that the estimated artefact size can be user dependent. To cope with this problem, we propose an algorithm to automatically quantify the size of such susceptibility artefacts. The algorithm is based on the analysis of a 3D surface generated from the 2D MR images. The results obtained by the automatic algorithm were compared to the manual measurements performed by study participants. The results show that the automatic and manual measurements follow the same trend. The clear advantage of the automated algorithm is the absence of the inter- and intra-observer variability. In addition, the algorithm also detects the slice containing the largest artefact which was not the case for the manual measurements.

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Erasmus, L. J., D. Hurter, M. Naude, H. G. Kritzinger, and S. Acho. "A short overview of MRI artefacts." South African Journal of Radiology 8, no. 2 (June 9, 2004): 13. http://dx.doi.org/10.4102/sajr.v8i2.127.

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Many different artefacts can occur during magnetic resonance imaging (MRI), some affecting the diagnostic quality, while others may be confused with pathology. An artefact is a feature appearing in an image that is not present in the original object. Artefacts can be classified as patient related, signal processing-dependent and hardware (machine)-related.This article presents an overview of MRI artefacts and possible rectifying methods.

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DU CRET, RENÉ P., ROBERT J. BOUDREAU, FRANK P. MAGUIRE, and SANDRA J. ALTHAUS. "Sigmoid Augmentation Artefact in Skeletal Imaging." Clinical Nuclear Medicine 13, no. 5 (May 1988): 375. http://dx.doi.org/10.1097/00003072-198805000-00021.

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Martins, Luciano Augusto Cano, Polyane Mazucatto Queiroz, Yuri Nejaim, Karla de Faria Vasconcelos, Francisco Carlos Groppo, and Francisco Haiter-Neto. "Evaluation of metal artefacts for two CBCT devices with a new dental arch phantom." Dentomaxillofacial Radiology 49, no. 5 (July 2020): 20190385. http://dx.doi.org/10.1259/dmfr.20190385.

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Objectives: To create a new phantom design to evaluate the real impact of artefacts caused by titanium on bone structures in cone beam CT images considering different positions and quantity of metals in the dental arch, with and without metal artefact reduction (MAR). Methods: A three cylindrical polymethyl methacrylate (PMMA) plate phantom was designed containing eight perforations arranged to simulate the lower dental arch in the intermediate plate. Three titanium cylinders were positioned in different locations and quantities to test different clinical conditions and to quantify the impact of the metal artefact around five bone cylinders. Scans were carried out in seven different protocols (Control, A-F) in two cone beam CT devices (OP300 Maxio and Picasso Trio). Eight regions of interest around each cortical and trabecular bone were used to measure the grey value standard deviation corresponding the artefact expression in the Image J software. Both the artefact expression and the MAR effect were assessed using the Wilcoxon, Friedman (Dunn) and Kruskal–Wallis tests (significance level of 5%). Results: For both devices, MAR was statistically efficient only for the protocols E, and F. Protocol F (three metals on the adjacent area of the analysis region) showed higher artefact expression when compared to the others. Conclusion: In conclusion, the new phantom design allowed the quantification of the metal artefact expression caused by titanium. The metal artefact expression is higher when more metal objects are positioned in the adjacent bone structures. MAR may not be effective to reduce artefact expression on the adjacencies of those objects for the devices studied.

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Yue Lee, Francis Chun, Christian Jenssen, and Christoph F. Dietrich. "A common misunderstanding in lung ultrasound: the comet tail artefact." Medical Ultrasonography 20, no. 3 (August 30, 2018): 379. http://dx.doi.org/10.11152/mu-1573.

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The comet tail artefact is probably one of the most commonly and imprecisely used to describe vertical artefacts found in lung ultrasound. Two distinct artefacts are commonly observed: the lung comets and the B-lines. Both artefacts differ with regard to generation mechanism and clinical significance. This review explores the current understanding and use of these two artefacts in lung ultrasound and suggests how to avoid the pitfalls related to confusing comet tail artefacts with other vertical artefacts.

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Mahon, Ciara, Peter Gatehouse, John Baksi, and Raad H. Mohiaddin. "The mysterious needle in the heart: a case report." European Heart Journal - Case Reports 4, no. 3 (May 3, 2020): 1–4. http://dx.doi.org/10.1093/ehjcr/ytaa083.

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Abstract Background A 53-year-old female with dyspnoea and atypical chest pain. Her electrocardiogram demonstrated a left bundle branch block, transthoracic echocardiogram demonstrated a mildly impaired left ventricle ejection fraction, and coronary angiogram revealed unobstructed coronary arteries. She was referred for cardiovascular magnetic resonance (CMR) for structural and functional assessment. Her imaging revealed an unexpected finding of an off-resonance artefact within the ventricle wall. This material was secondary to a ferromagnetic material. Case summary Chest X ray and computer tomography confirmed a needle-shaped structure in the ventricle wall. Understanding the basis of this off-resonance artefact aided in a new diagnosis, raised questions on the origin of the material, patient safety, and implementation of corrective strategies to optimize image acquisition. Discussion The continued development of CMR is revolutionizing our ability to establish diagnosis and guide patient treatment. The CMR sequences can be prone to artefact. This case highlights the importance of understanding the basis of CMR artefacts.

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Pitman, A. G., V. Kalff, B. Van Every, B. Risa, L. R. Barnden, and M. J. Kelly. "19. Is respiratory motion artefact independent of attenuation artefact?" Nuclear Medicine Communications 22, no. 8 (August 2001): 924. http://dx.doi.org/10.1097/00006231-200108000-00029.

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Buchanan, Allison, Carla Morales, Stephen Looney, and Sajitha Kalathingal. "Fish scale artefact on an intraoral imaging receptor." Dentomaxillofacial Radiology 46, no. 8 (December 2017): 20170224. http://dx.doi.org/10.1259/dmfr.20170224.

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11

Overweg, Johannes. "5185575 Magnetic resonance imaging apparatus with artefact reduction." Magnetic Resonance Imaging 11, no. 8 (January 1993): XLII. http://dx.doi.org/10.1016/0730-725x(93)90318-8.

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12

Sohani, Behnaz, James Puttock, Banafsheh Khalesi, Navid Ghavami, Mohammad Ghavami, Sandra Dudley, and Gianluigi Tiberi. "Developing Artefact Removal Algorithms to Process Data from a Microwave Imaging Device for Haemorrhagic Stroke Detection." Sensors 20, no. 19 (September 28, 2020): 5545. http://dx.doi.org/10.3390/s20195545.

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In this paper, we present an investigation of different artefact removal methods for ultra-wideband Microwave Imaging (MWI) to evaluate and quantify current methods in a real environment through measurements using an MWI device. The MWI device measures the scattered signals in a multi-bistatic fashion and employs an imaging procedure based on Huygens principle. A simple two-layered phantom mimicking human head tissue is realised, applying a cylindrically shaped inclusion to emulate brain haemorrhage. Detection has been successfully achieved using the superimposition of five transmitter triplet positions, after applying different artefact removal methods, with the inclusion positioned at 0°, 90°, 180°, and 270°. The different artifact removal methods have been proposed for comparison to improve the stroke detection process. To provide a valid comparison between these methods, image quantification metrics are presented. An “ideal/reference” image is used to compare the artefact removal methods. Moreover, the quantification of artefact removal procedures through measurements using MWI device is performed.

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Paranjpye, D., A. Mahabal, A. N. Ramaprakash, G. V. Panopoulou, K. Cleary, A. C. S. Readhead, D. Blinov, and K. Tassis. "Eliminating artefacts in polarimetric images using deep learning." Monthly Notices of the Royal Astronomical Society 491, no. 4 (November 28, 2019): 5151–57. http://dx.doi.org/10.1093/mnras/stz3250.

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ABSTRACT Polarization measurements done using Imaging Polarimeters such as the Robotic Polarimeter are very sensitive to the presence of artefacts in images. Artefacts can range from internal reflections in a telescope to satellite trails that could contaminate an area of interest in the image. With the advent of wide-field polarimetry surveys, it is imperative to develop methods that automatically flag artefacts in images. In this paper, we implement a Convolutional Neural Network to identify the most dominant artefacts in the images. We find that our model can successfully classify sources with 98 per cent true positive and 97 per cent true negative rates. Such models, combined with transfer learning, will give us a running start in artefact elimination for near-future surveys like WALOP.

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Santaella, Gustavo Machado, Ann Wenzel, Francisco Haiter-Neto, Pedro Luiz Rosalen, and Rubens Spin-Neto. "Impact of movement and motion-artefact correction on image quality and interpretability in CBCT units with aligned and lateral-offset detectors." Dentomaxillofacial Radiology 49, no. 1 (January 2020): 20190240. http://dx.doi.org/10.1259/dmfr.20190240.

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Objectives: To evaluate the impact of movement and motion-artefact correction systems on CBCT image quality and interpretability of simulated diagnostic tasks for aligned and lateral-offset detectors. Methods: A human skull simulating three diagnostic tasks (implant planning in the anterior maxilla, implant planning in the left-side-mandible and mandibular molar furcation assessment in the right-side-mandible) was mounted on a robot performing six movement types. Four CBCT units were used: Cranex 3Dx (CRA), Ortophos SL (ORT), Promax 3D Mid (PRO), and X1. Protocols were tested with aligned (CRA, ORT, PRO, and X1) and lateral-offset (CRA and PRO) detectors and two motion-artefact correction systems (PRO and X1). Movements were performed at one moment-in-time (t1), for units with an aligned detector, and three moments-in-time (t1-first-half of the acquisition, t2-second-half, t3-both) for the units with a lateral-offset detector. 98 volumes were acquired. Images were scored by three observers, blinded to the unit and presence of movement, for motion-related stripe artefacts, overall unsharpness, and interpretability. Fleiss’ κ was used to assess interobserver agreement. Results: Interobserver agreement was substantial for all parameters (0.66–0.68). For aligned detectors, in all diagnostic tasks a motion-artefact correction system influenced image interpretability. For lateral-offset detectors, the interpretability varied according to the unit and moment-in-time, in which the movement was performed. PRO motion-artefact correction system was less effective for the offset detector than its aligned counterpart. Conclusion: Motion-artefact correction systems enhanced image quality and interpretability for units with aligned detectors but were less effective for those with lateral-offset detectors.

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15

Dimarakis, Ioannis N., Sanjay Taribagil, and Kesava R. Mannur. "A Novel Cause of Artefact in Gunshot Trauma Imaging." Journal of Trauma: Injury, Infection, and Critical Care 60, no. 1 (January 2006): 241. http://dx.doi.org/10.1097/01.ta.0000200076.53905.7e.

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16

Shibutani, Hiroki, Kenichi Fujii, Rika Kawakami, Takahiro Imanaka, Kenji Kawai, Satoshi Tsujimoto, Koichiro Matsumura, et al. "Tangential signal dropout artefact in optical frequency domain imaging." EuroIntervention 17, no. 4 (July 2021): e326-e331. http://dx.doi.org/10.4244/eij-d-20-00014.

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17

Lee, Young Han, Kwan Kyu Park, Ho-Taek Song, Sungjun Kim, and Jin-Suck Suh. "Metal artefact reduction in gemstone spectral imaging dual-energy CT with and without metal artefact reduction software." European Radiology 22, no. 6 (February 4, 2012): 1331–40. http://dx.doi.org/10.1007/s00330-011-2370-5.

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18

Sweetlove, A., C. P. Herbst, C. Markgraaff, and I. Nel. "Identification of mammography image artefact: A random assortment of low density blemishes." South African Journal of Radiology 2, no. 1 (March 31, 1997): 10–11. http://dx.doi.org/10.4102/sajr.v2i1.1642.

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Following identification of an image artefact on a newly commissioned mammography system, the grid was initially not suspected as the cause as grid artefacts are generally associated with lines. A reference phantom image was taken at an accredited centre was used to resolve the problem. It is therefore felt to be essential for instructions not subject to peer evaluation to use phantoms.

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19

Han, Jason, Hao Xiang, William E. Ridley, and Lloyd J. Ridley. "Seagull sign: Respiratory motion artefact." Journal of Medical Imaging and Radiation Oncology 62 (October 2018): 46. http://dx.doi.org/10.1111/1754-9485.32_12785.

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20

Payne, M. "A novel panoramic artefact." Dentomaxillofacial Radiology 18, no. 3 (August 1989): 138–39. http://dx.doi.org/10.1259/dmfr.18.3.2637882.

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21

Serman, N. J. "A novel processing artefact." Dentomaxillofacial Radiology 18, no. 3 (August 1989): 140. http://dx.doi.org/10.1259/dmfr.18.3.2637883.

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22

Purser, Nicola J., Ian S. Armstrong, Heather A. Williams, Christine M. Tonge, and Richard S. Lawson. "Apical thinning: real or artefact?" Nuclear Medicine Communications 29, no. 4 (April 2008): 382–89. http://dx.doi.org/10.1097/mnm.0b013e3282f4a22e.

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23

Tan, T. H., and A. E. Boothroyd. "Uberschwinger artefact in computed radiographs." British Journal of Radiology 70, no. 832 (April 1997): 431. http://dx.doi.org/10.1259/bjr.70.832.9166087.

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Miljković, V., and D. Gajski. "ADAPTATION OF INDUSTRIAL HYPERSPECTRAL LINE SCANNER FOR ARCHAEOLOGICAL APPLICATIONS." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B5 (June 15, 2016): 343–45. http://dx.doi.org/10.5194/isprsarchives-xli-b5-343-2016.

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The spectral characteristic of the visible light reflected from any of archaeological artefact is the result of the interaction of its surface illuminated by incident light. Every particular surface depends on what material it is made of and/or which layers put on it has its spectral signature. Recent archaeometry recognises this information as very valuable data to extend present documentation of artefacts and as a new source for scientific exploration. However, the problem is having an appropriate hyperspectral imaging system available and adopted for applications in archaeology. In this paper, we present the new construction of the hyperspectral imaging system, made of industrial hyperspectral line scanner ImSpector V9 and CCD-sensor PixelView. The hyperspectral line scanner is calibrated geometrically, and hyperspectral data are geocoded and converted to the hyperspectral cube. The system abilities are evaluated for various archaeological artefacts made of different materials. Our experience in applications, visualisations, and interpretations of collected hyperspectral data are explored and presented.

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Miljković, V., and D. Gajski. "ADAPTATION OF INDUSTRIAL HYPERSPECTRAL LINE SCANNER FOR ARCHAEOLOGICAL APPLICATIONS." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B5 (June 15, 2016): 343–45. http://dx.doi.org/10.5194/isprs-archives-xli-b5-343-2016.

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The spectral characteristic of the visible light reflected from any of archaeological artefact is the result of the interaction of its surface illuminated by incident light. Every particular surface depends on what material it is made of and/or which layers put on it has its spectral signature. Recent archaeometry recognises this information as very valuable data to extend present documentation of artefacts and as a new source for scientific exploration. However, the problem is having an appropriate hyperspectral imaging system available and adopted for applications in archaeology. In this paper, we present the new construction of the hyperspectral imaging system, made of industrial hyperspectral line scanner ImSpector V9 and CCD-sensor PixelView. The hyperspectral line scanner is calibrated geometrically, and hyperspectral data are geocoded and converted to the hyperspectral cube. The system abilities are evaluated for various archaeological artefacts made of different materials. Our experience in applications, visualisations, and interpretations of collected hyperspectral data are explored and presented.

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Strudwick, Ruth M. "The radiographic image: A cultural artefact?" Radiography 20, no. 2 (May 2014): 143–47. http://dx.doi.org/10.1016/j.radi.2013.10.009.

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27

Atkinson, David. "Incoherent artefact correction using PPI." NMR in Biomedicine 19, no. 3 (2006): 362–67. http://dx.doi.org/10.1002/nbm.1045.

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Steel, Robin, Tamie L. Poepping, Rosemary S. Thompson, and Charles Macaskill. "Origins of the edge shadowing artefact in medical ultrasound imaging." Ultrasound in Medicine & Biology 30, no. 9 (September 2004): 1153–62. http://dx.doi.org/10.1016/j.ultrasmedbio.2004.07.014.

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Pabst, G., K. Strobel, and J. Zehnder. "The value of the twinkling artefact for the diagnosis of sialolithiasis of the large salivary glands." Journal of Laryngology & Otology 132, no. 2 (December 18, 2017): 162–67. http://dx.doi.org/10.1017/s002221511700250x.

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AbstractObjective:The imaging of stones in the salivary glands and ducts poses a challenge, even to experienced ultrasound examiners. This study investigated whether the ‘twinkling artefact’, which occurs at internal calcific foci during Doppler ultrasound examinations, is useful for detecting salivary gland stones.Methods:In a model test, 20 salivary stones were analysedin vitro, via Doppler ultrasound, with regard to their representability and the triggering of the twinkling artefact. In a follow-up study, 28 patients with sialolithiasis and food-related large salivary gland swellings were examined, using both power and colour Doppler modes, with regard to the twinkling artefact. All ultrasound examinations were performed by an experienced examiner and retrospectively graded by two experienced sonographers.Results:All stones could reliably be detected using the twinkling artefact in the model test. Twenty-seven of 28 salivary stones (96 per cent) also showed twinklingin vivo, during patient assessment. The power Doppler mode showed a significantly higher intensity level of twinkling than the colour Doppler mode (p< 0.0001).Conclusion:The twinkling artefact is a very reliable sign for the diagnosis of sialolithiasis. Power Doppler is superior to colour Doppler for detection of the twinkling artefact.

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Ricci, S., F. Antonelli, and C. Sacco Perasso. "ASPECTS OF BIODETERIORATION OF LAPIDEOUS SUBMERGED ARTEFACTS: 3D METHODOLOGIES APPLICATION." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-5/W5 (April 9, 2015): 191–94. http://dx.doi.org/10.5194/isprsarchives-xl-5-w5-191-2015.

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Submerged stone archaeological artefacts are bioeroded by endolithic microbiota (cyanobacteria, algae and fungi) and macroborers (Porifera, Bivalvia and Sipuncula). Optical microscope and SEM observations permit to analyse the bioerosion traces and to identify bioeroders. Data obtained with these techniques cannot be used to estimate volumes of material bioeroded. This aspect require the need to collect three-dimensional, close-range data from artefact. In this work we illustrate two 3D imaging techniques used to study bioerosion phenomena of underwater Cultural Heritage. In particular Digital Video Microscope permit the elaboration of 3D images, which are widely employed for close-range acquisitions. Underwater Laser Scanner documents the in situ degradation of submerged artefacts. This research aims to sensitize specialist figures in the study 3D offering a starting point for future collaborations that could lead to interesting results.

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Oh, Lawrence Chia-Wei, Kenneth Kwok-Pan Lau, Ashwini Devapalasundaram, Kevin Buchan, Ahilan Kuganesan, and Minh Huynh. "Efficacy of fine focal spot technique in CT angiography of neck." British Journal of Radiology 92, no. 1100 (August 2019): 20190083. http://dx.doi.org/10.1259/bjr.20190083.

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Objectives: Focal spot size partially defines spatial resolution of a CT system. Many CT tubes have two focal spot sizes, with the finer one allowing more detailed imaging at the cost of photon intensity and increased heat production. Improved X-ray technology and advancement of various generations of iterative reconstruction allow the use of fine focal spot technique in CT angiography. CT neck angiography (CTNA) has been commonly performed as part of stroke imaging or in the trauma setting. This prospective study aimed to assess the efficacy of fine focal spot scanning in vessel clarity improvement, vessel calcification and arterial pulsation artefact reduction on CTNA. Methods and materials: Consecutive adult patients of all ages and genders who presented for CTNA were included. All CTNA were scanned with standard focal spot size (SFSS) of 1 × 1 mm in first 4 months while the CTNA in the following 4 months with fine focal spot size (FFSS) of 0.5 × 1 mm. Vessel clarity, calcification and arterial pulsation artefact of arch of aorta, brachiocephalic, subclavian, common carotid, carotid bifurcation, internal carotid, external carotid and vertebral arteries were assessed randomly using a 5-point scale by two blinded radiologists. Results were compared. Results: There were 43 patients (mean age 60) with 97 calcified arterial segments in SFSS and 48 patients (mean age 62) with 113 calcified arterial segments in FFSS. 30 % of patients had > 50% carotid artery stenosis. No occlusion or dissection was found in the remaining arteries. Mann-Whitney test showed FFSS performed significantly better for vessel clarity (U: 48238.50, p < .001,r: 0.556) and calcification artefact reduction (U: 2040.50, p < .001,r: 0.564). There was no significant reduction for arterial pulsation artefact. Conclusion: Fine focal spot technique improves vessel clarity and reduces calcification blooming artefact in CTNA. These benefits may potentially improve the assessment of arterial luminal stenosis and vessel wall pathology, including plaque morphology. Advances in knowledge: Beam hardening artefact from calcification particularly in the vessel wall can often reduce the clarity of vessel lumen thus affect accurate assessment of luminal stenosis. Fine focal spot technique has the advantages of reducing beam-hardening artefact of vessel wall calcifications and improving vessel wall clarity, thus it may potentially improve the assessment of arterial luminal stenosis and vessel wall pathology, including plaque morphology. It may become an important CT imaging technique in near future.

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Purser, N. J., H. A. Williams, C. M. Tonge, and R. S. Lawson. "21 Apical thinning ??? real or artefact?" Nuclear Medicine Communications 28, no. 3 (March 2007): A7. http://dx.doi.org/10.1097/00006231-200703000-00036.

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Campbell, R. S. D., C. J. Baudouin, and A. Harrison. "An unusual cause of MRI artefact." Clinical Radiology 50, no. 3 (March 1995): 198. http://dx.doi.org/10.1016/s0009-9260(05)83059-4.

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34

Dandapani, Madhumita, and S. Rajagopalan. "Movement artefact – A pain in the neck!" Radiography 13, no. 1 (February 2007): 81–82. http://dx.doi.org/10.1016/j.radi.2005.10.009.

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35

Fukasawa, Yuriko. "TRI: three-dimensional imaging for recording and analysing stone-artefact concentrations." Antiquity 66, no. 250 (March 1992): 93–97. http://dx.doi.org/10.1017/s0003598x00081072.

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Software for computer graphics is rapidly growing in power. Here is an application which enables a complex three-dimensional assemblage to be recorded and explored in its full spatial order. ANTIQUITY's illustrations – stationary in monochrome two dimensions – can so little show what the technique offers as to underline Ms Fukasawa's point.

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Crofts, S., and A. Campbell. "A source of artefact during general anaesthesia for magnetic resonance imaging." Anaesthesia 48, no. 7 (July 1993): 643. http://dx.doi.org/10.1111/j.1365-2044.1993.tb07152.x.

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Haase, C., D. Schäfer, M. Kim, S. J. Chen, J. D. Carroll, P. Eshuis, O. Dössel, and M. Grass. "First pass cable artefact correction for cardiac C-arm CT imaging." Physics in Medicine and Biology 59, no. 14 (June 24, 2014): 3861–75. http://dx.doi.org/10.1088/0031-9155/59/14/3861.

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Förster, Ronny, Kai Wicker, Walter Müller, Aurélie Jost, and Rainer Heintzmann. "Motion artefact detection in structured illumination microscopy for live cell imaging." Optics Express 24, no. 19 (September 14, 2016): 22121. http://dx.doi.org/10.1364/oe.24.022121.

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Sherwood, Victoria, John Civale, Ian Rivens, David J. Collins, Martin O. Leach, and Gail R. ter Haar. "Development of a Hybrid Magnetic Resonance and Ultrasound Imaging System." BioMed Research International 2014 (2014): 1–16. http://dx.doi.org/10.1155/2014/914347.

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A system which allows magnetic resonance (MR) and ultrasound (US) image data to be acquired simultaneously has been developed. B-mode and Doppler US were performed inside the bore of a clinical 1.5 T MRI scanner using a clinical 1–4 MHz US transducer with an 8-metre cable. Susceptibility artefacts and RF noise were introduced into MR images by the US imaging system. RF noise was minimised by using aluminium foil to shield the transducer. A study of MR and B-mode US image signal-to-noise ratio (SNR) as a function of transducer-phantom separation was performed using a gel phantom. This revealed that a 4 cm separation between the phantom surface and the transducer was sufficient to minimise the effect of the susceptibility artefact in MR images. MR-US imaging was demonstratedin vivowith the aid of a 2 mm VeroWhite 3D-printed spherical target placed over the thigh muscle of a rat. The target allowed single-point registration of MR and US images in the axial plane to be performed. The system was subsequently demonstrated as a tool for the targeting and visualisation of high intensity focused ultrasound exposure in the rat thigh muscle.

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Ge, Nan, Stéphane Chevalier, James Hinebaugh, Ronnie Yip, Jongmin Lee, Patrick Antonacci, Toshikazu Kotaka, Yuichiro Tabuchi, and Aimy Bazylak. "Calibrating the X-ray attenuation of liquid water and correcting sample movement artefacts duringin operandosynchrotron X-ray radiographic imaging of polymer electrolyte membrane fuel cells." Journal of Synchrotron Radiation 23, no. 2 (February 10, 2016): 590–99. http://dx.doi.org/10.1107/s1600577515023899.

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Synchrotron X-ray radiography, due to its high temporal and spatial resolutions, provides a valuable means for understanding thein operandowater transport behaviour in polymer electrolyte membrane fuel cells. The purpose of this study is to address the specific artefact of imaging sample movement, which poses a significant challenge to synchrotron-based imaging for fuel cell diagnostics. Specifically, the impact of the micrometer-scale movement of the sample was determined, and a correction methodology was developed. At a photon energy level of 20 keV, a maximum movement of 7.5 µm resulted in a false water thickness of 0.93 cm (9% higher than the maximum amount of water that the experimental apparatus could physically contain). This artefact was corrected by image translations based on the relationship between the false water thickness value and the distance moved by the sample. The implementation of this correction method led to a significant reduction in false water thickness (to ∼0.04 cm). Furthermore, to account for inaccuracies in pixel intensities due to the scattering effect and higher harmonics, a calibration technique was introduced for the liquid water X-ray attenuation coefficient, which was found to be 0.657 ± 0.023 cm−1at 20 keV. The work presented in this paper provides valuable tools for artefact compensation and accuracy improvements for dynamic synchrotron X-ray imaging of fuel cells.

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Leclercq, Yves, Jessica Schrouff, Quentin Noirhomme, Pierre Maquet, and Christophe Phillips. "fMRI Artefact Rejection and Sleep Scoring Toolbox." Computational Intelligence and Neuroscience 2011 (2011): 1–11. http://dx.doi.org/10.1155/2011/598206.

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We started writing the “fMRI artefact rejection and sleep scoring toolbox”, or “FAST”, to process our sleep EEG-fMRI data, that is, the simultaneous recording of electroencephalographic and functional magnetic resonance imaging data acquired while a subject is asleep. FAST tackles three crucial issues typical of this kind of data: (1) data manipulation (viewing, comparing, chunking, etc.) of long continuous M/EEG recordings, (2) rejection of the fMRI-induced artefact in the EEG signal, and (3) manual sleep-scoring of the M/EEG recording. Currently, the toolbox can efficiently deal with these issues via a GUI, SPM8 batching system or hand-written script. The tools developed are, of course, also useful for other EEG applications, for example, involving simultaneous EEG-fMRI acquisition, continuous EEG eye-balling, and manipulation. Even though the toolbox was originally devised for EEG data, it will also gracefully handle MEG data without any problem. “FAST” is developed in Matlab as an add-on toolbox for SPM8 and, therefore, internally uses its SPM8-meeg data format. “FAST” is available for free, under the GNU-GPL.

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Watson, T. F. "Fact and Artefact in Confocal Microscopy." Advances in Dental Research 11, no. 4 (November 1997): 433–41. http://dx.doi.org/10.1177/08959374970110040901.

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High-resolution confocal microscopic images may be made of either the surface of a sample or beneath the surface. These images can be likened to optical tomograms, giving thin (> 0.35 μm) slices up to 200 μm below the surface of a transparent tissue: With microscopes running under normal conditions, the optical section thickness will be >1 μm and the effective penetration into enamel and dentin a maximum of 100 μm. For maximum resolution, high-quality, high-numerical-aperture objectives should be used. Refractive index matching of the lens immersion media and the substrate will avoid distortions of images in the optical axis. Such errors could occur when imaging a considerable distance (> 40 μm) into a cell containing water, with an oil immersion objective above the cover slip. Care should be taken in the interpretation of computerized z axis reconstructions made from serial optical sections: Their validity should be checked with equivalent views made with the sample oriented in the same direction as the reconstruction. The use of fluorescent dyes in microscopy is a very powerful investigative technique. It is important that the dyes used not be labile and that they be well-fixed to the materials being examined, or the images may indicate the dye distribution rather than the material to which it is "attached". Multiple labeling experiments must have crossover control experiments to verify the distribution of the individual dyes. Valuable information can often be gained by combining information from both reflection and fluorescence images. Two-photon laser excitation of dyes gives the potential for greater depth penetration and improved resolution.

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Horstmeier, Carolin, Annette B. Ahrberg, Dagmar Berner, Janina Burk, Claudia Gittel, Aline Hillmann, Julia Offhaus, and Walter Brehm. "In Vivo Magic Angle Magnetic Resonance Imaging for Cell Tracking in Equine Low-Field MRI." Stem Cells International 2019 (December 17, 2019): 1–9. http://dx.doi.org/10.1155/2019/5670106.

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The magic angle effect increases the MRI signal of healthy tendon tissue and could be used for more detailed evaluation of tendon structure. Furthermore, it could support the discrimination of hypointense artefacts induced by contrast agents such as superparamagnetic iron oxide used for cell tracking. However, magic angle MRI of the equine superficial digital flexor tendon has not been accomplished in vivo in standing low-field MRI so far. The aim of this in vivo study was to evaluate the practicability of this magic angle technique and its benefit for tracking superparamagnetic iron oxide-labelled multipotent mesenchymal stromal cells. Six horses with induced tendinopathy in their forelimb superficial digital flexor tendons were injected locally either with superparamagnetic iron oxide-labelled multipotent mesenchymal stromal cells or serum. MRI included standard and magic angle image series in T1- and T2∗-weighted sequences performed at regular intervals. Image analysis comprised blinded evaluation and quantitative assessment of signal-to-noise ratio. The magic angle technique enhanced the tendon signal-to-noise ratio (P<0.001). Hypointense artefacts were observable in the cell-injected superficial digital flexor tendons over 24 weeks and artefact signal-to-noise ratio differed significantly from tendon signal-to-noise ratio in the magic angle images (P<0.001). Magic angle imaging of the equine superficial digital flexor tendon is feasible in standing low-field MRI. The current data demonstrate that the technique improves discrimination of superparamagnetic iron oxide-induced artefacts from the surrounding tendon tissue.

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Lim, P., J. Barber, and J. Sykes. "Evaluation of dual energy CT and iterative metal artefact reduction (iMAR) for artefact reduction in radiation therapy." Australasian Physical & Engineering Sciences in Medicine 42, no. 4 (October 10, 2019): 1025–32. http://dx.doi.org/10.1007/s13246-019-00801-1.

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Magnusson, A., E. Radecka, M. Lönnemark, and H. Raland. "Computed-tomography-guided punctures using a new guidance device." Acta Radiologica 46, no. 5 (August 2005): 505–9. http://dx.doi.org/10.1080/02841850510021508.

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Purpose: To evaluate a new adjunctive guidance device, a puncture guide, constructed to simplify computed tomography (CT)-guided punctures and to make the procedure more accurate and safe. Material and Methods: 17 patients referred for CT-guided punctures were included in the study. There were 10 thoracic and 7 abdominal or pelvic lesions with a mean maximum diameter of 29±18 mm. All punctures were performed using a laser guide combined with the new device. The needle guide created a streak artefact in the image, indicating the needle path. Results: The puncture was successful at the first attempt in 15 of the 17 patients. The artefact was visible in all patients, and in the majority there was a distinct artefact reaching from the entry point to the lesion. The deviation between the angle of the streak artefact and the final angle of the needle was 1.1°. Conclusion: The benefits of the puncture guide were the artefact pointing at the target, the needle support, and accuracy when performing CT-guided punctures.

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Kidoh, Masafumi, Daisuke Utsunomiya, Osamu Ikeda, Yoshitaka Tamura, Seitaro Oda, Yoshinori Funama, Hideaki Yuki, et al. "Reduction of metallic coil artefacts in computed tomography body imaging: effects of a new single-energy metal artefact reduction algorithm." European Radiology 26, no. 5 (August 14, 2015): 1378–86. http://dx.doi.org/10.1007/s00330-015-3950-6.

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Indiran, Venkatraman, L. Raguram Subha, and Jagannathan Kokilavani. "Kajal-induced Artefact Simulating a Ciliary Body Tumor on Magnetic Resonance Imaging." Türk Oftalmoloji Dergisi 48, no. 3 (June 29, 2018): 158–59. http://dx.doi.org/10.4274/tjo.52323.

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Brosch, Nicole, Svorad Štolc, and Doris Antensteiner. "Warping-based Motion Artefact Compensation for Multi-Line Scan Light Field Imaging." Electronic Imaging 2018, no. 15 (January 28, 2018): 273–1. http://dx.doi.org/10.2352/issn.2470-1173.2018.15.coimg-273.

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Vidal, F. P., J. M. Létang, G. Peix, and P. Cloetens. "Investigation of artefact sources in synchrotron microtomography via virtual X-ray imaging." Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 234, no. 3 (June 2005): 333–48. http://dx.doi.org/10.1016/j.nimb.2005.02.003.

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Volegov, P., L. Schultz, and M. Espy. "On a ghost artefact in ultra low field magnetic resonance relaxation imaging." Journal of Magnetic Resonance 243 (June 2014): 98–106. http://dx.doi.org/10.1016/j.jmr.2014.04.005.

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